# Last edited on 2007-01-13 21:13:16 by stolfi

Actual clock resolutions measured in some machines:

  * AMD Duron 1110.001 MHz

      --------------------------------------------------------------------
                                                                resolution
                                                --------------------------
      clock                                          nominal        actual
      ----------------------------------------  --------------  ----------
      nanoclock with CLOCK_PROCESS_CPUTIME_ID         0.001 us     4000 us
      nanoclock with CLOCK_THREAD_CPUTIME_ID          0.001 us     4000 us
      nanoclock with CLOCK_MONOTONIC               4000.250 us      <10 us
      nanoclock with CLOCK_REALTIME                4000.250 us      <10 us
      POSIX UTC {time} function                 1000000.000 us  1000000 us
      ANSI {clock} function                           1.000 us    10000 us
      Unix {times} function (user)                10000.000 us    10000 us   
      Unix {times} function (elapsed)             10000.000 us    10000 us 
      --------------------------------------------------------------------
      nanosleep with CLOCK_MONOTONIC                           >1000000 us
      nanosleep with CLOCK_REALTIME                            >1000000 us
      POSIX {sleep} function                    1000000.000 us >1000000 us
      BSD/SUSv2 {usleep} function
      --------------------------------------------------------------------